I think it's pretty sure some of it was.

Just consider that the X in math is not a latin X but a Greek Χ (chi) :)

Most mathematical notation wasn't invented until centuries later. At the time, they would just write calculations out in words. In particular, the use of x representing an unknown quantity was introduced by Descartes: https://en.wikipedia.org/wiki/History_of_algebra#The_symbol_...